2 * Real Time Clock Driver Test/Example Program
5 * gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
7 * Copyright (C) 1996, Paul Gortmaker.
9 * Released under the GNU General Public License, version 2,
10 * included herein by reference.
15 #include <linux/rtc.h>
16 #include <sys/ioctl.h>
18 #include <sys/types.h>
25 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
29 * This expects the new RTC class driver framework, working with
30 * clocks that will often not be clones of what the PC-AT had.
31 * Use the command line to specify another RTC if you need one.
33 static const char default_rtc[] = "/dev/rtc0";
35 static struct rtc_time cutoff_dates[] = {
37 .tm_year = 70, /* 1970 -1900 */
40 /* signed time_t 19/01/2038 3:14:08 */
50 .tm_year = 199, /* 2099 -1900 */
54 .tm_year = 200, /* 2100 -1900 */
57 /* unsigned time_t 07/02/2106 7:28:15*/
68 /* signed time on 64bit in nanoseconds 12/04/2262 01:47:16*/
75 .tm_year = 362, /* 2262 -1900 */
81 static int compare_dates(struct rtc_time *a, struct rtc_time *b)
83 if (a->tm_year != b->tm_year ||
84 a->tm_mon != b->tm_mon ||
85 a->tm_mday != b->tm_mday ||
86 a->tm_hour != b->tm_hour ||
87 a->tm_min != b->tm_min ||
88 ((b->tm_sec - a->tm_sec) > 1))
94 int main(int argc, char **argv)
96 int i, fd, retval, irqcount = 0, dangerous = 0;
97 unsigned long tmp, data;
98 struct rtc_time rtc_tm;
99 const char *rtc = default_rtc;
100 struct timeval start, end, diff;
112 fprintf(stderr, "usage: rtctest [rtcdev] [d]\n");
116 fd = open(rtc, O_RDONLY);
123 fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
125 /* Turn on update interrupts (one per second) */
126 retval = ioctl(fd, RTC_UIE_ON, 0);
128 if (errno == EINVAL) {
130 "\n...Update IRQs not supported.\n");
133 perror("RTC_UIE_ON ioctl");
137 fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
140 for (i=1; i<6; i++) {
141 /* This read will block */
142 retval = read(fd, &data, sizeof(unsigned long));
147 fprintf(stderr, " %d",i);
152 fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
154 for (i=1; i<6; i++) {
155 struct timeval tv = {5, 0}; /* 5 second timeout on select */
159 FD_SET(fd, &readfds);
160 /* The select will wait until an RTC interrupt happens. */
161 retval = select(fd+1, &readfds, NULL, NULL, &tv);
166 /* This read won't block unlike the select-less case above. */
167 retval = read(fd, &data, sizeof(unsigned long));
172 fprintf(stderr, " %d",i);
177 /* Turn off update interrupts */
178 retval = ioctl(fd, RTC_UIE_OFF, 0);
180 perror("RTC_UIE_OFF ioctl");
185 /* Read the RTC time/date */
186 retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
188 perror("RTC_RD_TIME ioctl");
192 fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
193 rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
194 rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
196 /* Set the alarm to 5 sec in the future, and check for rollover */
198 if (rtc_tm.tm_sec >= 60) {
202 if (rtc_tm.tm_min == 60) {
206 if (rtc_tm.tm_hour == 24)
209 retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
211 if (errno == EINVAL) {
213 "\n...Alarm IRQs not supported.\n");
217 perror("RTC_ALM_SET ioctl");
221 /* Read the current alarm settings */
222 retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
224 if (errno == EINVAL) {
226 "\n...EINVAL reading current alarm setting.\n");
229 perror("RTC_ALM_READ ioctl");
233 fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
234 rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
236 /* Enable alarm interrupts */
237 retval = ioctl(fd, RTC_AIE_ON, 0);
239 if (errno == EINVAL || errno == EIO) {
241 "\n...Alarm IRQs not supported.\n");
245 perror("RTC_AIE_ON ioctl");
249 fprintf(stderr, "Waiting 5 seconds for alarm...");
251 /* This blocks until the alarm ring causes an interrupt */
252 retval = read(fd, &data, sizeof(unsigned long));
258 fprintf(stderr, " okay. Alarm rang.\n");
260 /* Disable alarm interrupts */
261 retval = ioctl(fd, RTC_AIE_OFF, 0);
263 perror("RTC_AIE_OFF ioctl");
268 /* Read periodic IRQ rate */
269 retval = ioctl(fd, RTC_IRQP_READ, &tmp);
271 /* not all RTCs support periodic IRQs */
272 if (errno == EINVAL) {
273 fprintf(stderr, "\nNo periodic IRQ support\n");
276 perror("RTC_IRQP_READ ioctl");
279 fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
281 fprintf(stderr, "Counting 20 interrupts at:");
284 /* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
285 for (tmp=2; tmp<=64; tmp*=2) {
287 retval = ioctl(fd, RTC_IRQP_SET, tmp);
289 /* not all RTCs can change their periodic IRQ rate */
290 if (errno == EINVAL) {
292 "\n...Periodic IRQ rate is fixed\n");
295 perror("RTC_IRQP_SET ioctl");
299 fprintf(stderr, "\n%ldHz:\t", tmp);
302 /* Enable periodic interrupts */
303 retval = ioctl(fd, RTC_PIE_ON, 0);
305 perror("RTC_PIE_ON ioctl");
309 for (i=1; i<21; i++) {
310 gettimeofday(&start, NULL);
312 retval = read(fd, &data, sizeof(unsigned long));
317 gettimeofday(&end, NULL);
318 timersub(&end, &start, &diff);
319 if (diff.tv_sec > 0 ||
320 diff.tv_usec > ((1000000L / tmp) * 1.10)) {
321 fprintf(stderr, "\nPIE delta error: %ld.%06ld should be close to 0.%06ld\n",
322 diff.tv_sec, diff.tv_usec,
328 fprintf(stderr, " %d",i);
333 /* Disable periodic interrupts */
334 retval = ioctl(fd, RTC_PIE_OFF, 0);
336 perror("RTC_PIE_OFF ioctl");
345 fprintf(stderr, "\nTesting problematic dates\n");
347 for (i = 0; i < ARRAY_SIZE(cutoff_dates); i++) {
348 struct rtc_time current;
350 /* Write the new date in RTC */
351 retval = ioctl(fd, RTC_SET_TIME, &cutoff_dates[i]);
353 perror("RTC_SET_TIME ioctl");
359 retval = ioctl(fd, RTC_RD_TIME, ¤t);
361 perror("RTC_RD_TIME ioctl");
365 if(compare_dates(&cutoff_dates[i], ¤t)) {
366 fprintf(stderr,"Setting date %d failed\n",
367 cutoff_dates[i].tm_year + 1900);
371 cutoff_dates[i].tm_sec += 5;
373 /* Write the new alarm in RTC */
374 retval = ioctl(fd, RTC_ALM_SET, &cutoff_dates[i]);
376 perror("RTC_ALM_SET ioctl");
382 retval = ioctl(fd, RTC_ALM_READ, ¤t);
384 perror("RTC_ALM_READ ioctl");
388 if(compare_dates(&cutoff_dates[i], ¤t)) {
389 fprintf(stderr,"Setting alarm %d failed\n",
390 cutoff_dates[i].tm_year + 1900);
394 fprintf(stderr, "Setting year %d is OK \n",
395 cutoff_dates[i].tm_year + 1900);
398 fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");